Cementing tool



Jan. 14, 1964 R. R. JARBOE, JR.. ETAL CEMENTING TOOL 2 Sheets-Sheet l 7IN V EN TOR.

Filed March 14, 1960 RALPH R. JARBOEJR DON C. HENNIGAN ATTORNEY Jan. 14,1964 R. R. JARBOE, JR.. ETAL 3,117,627

CEMENTING TOOL 2 SheetsSheet 2 Filed March 14, 1960 INVENTORS RALPH R.JARBOE JR. DON C..HENNIGAN WMM??? 9m .w i

ATTORNEY ite This invention relates to cementing tools and moreparticularly to a down hole cementing tool for use in forming cementcasing or conduit within bore holes.

Conventional well completion practices involve placing pie-formed metalconduit or casing within the bore hole and then cementing this string ofcasing in place by forcing cement into the annular space between thewall of the bore hole and the outer wall of the casing. Such methods ofcementing casing create numerous problems such as mud channeling, cementstratification, loss of fluid to the formation which the bore holepenetrates and flash set. Also, considerable difficulty is frequentlyexperienced in centralizing the casing within the bore hole. Due tothese dificulties the casing is rarely cemented throughout its entirelength except in very shallow wells. As a result, corrosion of the metalcasing and casing joint leaks are very common and locating and patchingsuch leaks is frequently extremely difficult.

The above mentioned diliiculties may be substantially eliminated by formng a cement well casing in place without the use of conventional metalcasing. It is, therefore, an object or" the present invention to providean improved cementing tool for forming cement casing within a bore hole.

For a better understanding of the invention reference should be had tothe accompanying drawings in which:

FEGURE 1 is a side elevation view partially in vertical section taken asindicated by the line AA of FIG. 2 and showing a down hole cementingtool constructed in accordance with the invention;

FZGURE 2 is a sectional view taken as indicated by line 2-2 of FIGURE 1;

FTGURE 3 is a plan view of a cement wipe plug suitable for use with thecementing tool shown in FIGURE 1;

FIGURE 4 is a sectional elevation view taken as indicated by line 4-4FTGURE 3;

FIGURE 5 is an elevation view sirnil-ar to FIGURE 1, partly in verticalsection taken as indicated by line A-A of FIG. '2 and showing a laterstage in the formation or" a cement casing using 16 apparatus shown inFIGURE 1; and

FIGURE 6 is an elevation view similar to FIGURE partly in verticalsection taken as indicated by line A-A of FIG. 2 and showing a stilllater stage in the formation of the cement casing.

Referring to the drawings, FEGURES l and 2 show a down hole cementingtool 11 adapted for use in forming a cement casing in a bore hole 12.The cementing tool it includes a generally cylindrical mandrel 13 havingan axial fluid passageway 14 extending from the top of the mandrel andterminating in the lower portion thereof. The upper end of the mandrel13 is preferably adapted to receive a suitable conduit or string oftubing such as a drill stem or tubing 16 through which fluid or cementmay be passed to the axial passageway 14 of the mandrel. Alternatively,the portion of tubing 16 shown in FIGURE 1 may form an integral part ofthe mandrel 13. in any case the portion of the tubing 16 shown in FIGURE1 may be considered a portion of the cementing tool 1 1. A plurality ofgenerally radial fluid passageways 17 extend from the lower portion ofthe axial passageway 14 to the exterior of the mandrel. The mandrel i3is also States Patent 0 "Ice provided with longitudinally extendingperipheral passageways 18. As best shown in FIGURE 1, the peripheralpassageways 18 provide fluid cormnunication between the exterior of theupper portion of the mandrel and the bottom of the mandrel. Aconventional one way check valve 19 is provided in the bottom of themandrel l3 and is arranged so as to allow passage of fluid through theperipheral passageways 18 to the space below the mandrel withoutallowing passage of any fluid in the reverse direction.

The upper portion of the cementing tool 11 is preferably provided with aradially extending formation scratcher such as 41 of conventional designand adapted to dislodge filter cake from the bore hole 12 as describedbelow. The upper portion of the mandrel may be provided with acollecting collar 42 secured around the mandrel immediately below theopenings of the passageways 18 and extending outwardly and upwardly fromthe point of contact with the mandrel to provide a suitable collectingfunnel for collecting solids dislodged by the formation scratcher 41.Collecting collar 42 may be of suitable material such as rubber and ispreferably mounted on the mandrel by frictional engagement therewith.

Centralizers 31 and 32 are preferably provided for centering thecementing tool 11 in the bore hole 12. The centralizer 31 is a pull elfcentralizer adapted to remain embedded in the first batch of cementinjected into the bore hole while the centralizer 32 is a fixedcentralizer adapted to remain fixed to the cementing tool. As shown inFIG. 1, the centralizer 32 may comprise outwardly bowed metal straps 33secured to the cementing tool by collars 34. Similarly, the pull offcentralizer 3-1 may comprise outwardly bowed tmetal straps 36 which passaround the end of the mandrel and are secured thereto by a collar 37.The collar 37 may be separate from or integral with the straps 36 andholds the centralizer 31 on the mandrel with a friction fit sufiicientlyloose so that the centralizer 31 may remain embedded in a batch ofcement when the mandrel 13 is rotated and withdrawn therefrom asdescribed below. The straps 36 are shaped so as to allow passage offluid through the passageway 18 and valve 19 as described above.

FIGURES 3 and 4 show a cement wipe plug 51 adapted to be forced down theaxial passageway 14 of the mandrel 13 for clearing cement therefrom asdescribed below. As shown in FIGURES 3 and 4 the Wipe plug 51 has a bodywhich includes an outer jacket 52 having a plurality of longitudinallyspaced circumferential flanges 53 of resilient material such as rubberextending outwardly therefrom and preferably integral therewith. Aninterior liner 54 of non-resilient material such as cast aluminum formsat least a portion of a generally cylindrical valve chamber 55 withinthe wipe plug 5 The lower end of the wipe plug 51 takes the form of avalve seat 56 adapted to receive valve means such as a ball valve 57.Spring means such as a spring is provided for urging the valve meansinto engagement with the valve seat. This may be accomplished in anysuitable manner such as by forming the valve 57 on the end of a rod 59which may be provided with an eye 61 at its upper end for receivingretrieving means such as a wire line 63. The rod 59 may also be providedat an intermediate point with an outwardly extending shoulder 62 forengaging the spring 58. Suitable means such as a perforated plate 64 maybe provided for engaging the spring 58 at the upper end of the valvechamber 55. From FIGURE 4 it can be seen that while the perforated plate64 provides free passage for fluids and allows vertical movement of therod 59, the spring 58 is confined between the plate 64- and the shoulder62 so that the spring 58 constantly urges the valve 57 into engagementwith the valve seat 56.

In operation, the cementing tool 11 is lowered down 3 the bore hole 12to the lowest point to be cemented as shown for instance in FIGURE 1.The mandrel 13 is centered in the bore hole by the pull off centralizer31 and fixed centralizer 32. Cement is then injected through the drillstem to, axial passageway 14 and radial passagei'ays 17. The quantity ofcement injected at this time is preferably sufiiciently small so thatthe level of cement in the bore hole does not extend above the top ofthe mandrel. This quantity of cement may be estimated but is preferablydetermined by gauging the diameter of the bore hole with a conventionalgauging tool prior to introducing the mandrel into the hole. Afterinjection of this first stage of cement the wipe plug 51 is injecteddown the drill stem and axial passageway with suitable fluid such asdrilling mud to wipe cement therefrom. During injection of the wipe plugthe valve 57 remains seated on the valve seat 56 thereby preventingpassage of cement upwardly through the plug and insuring that all cementin the drill stem 16 and axial passageway 14 is forced out through theradial passageways 17 into the bore hole surrounding the mandrel. Whenthe wipe plug 51 reaches the bottom of the axial passageway 14 (FIGURE5) the wipe plug is left in position in order to prevent back flow ofcement through the passageways 17. While the first stage of cement issetting the mandrel is slowly rotated either intermittently orcontinuously. When the cement is sufficiently set the cement wipe plug51 is retrieved by the wire line 63. During withdrawal of the wipe plugthe upward force of the wire line 63 acting on the rod 59 compresses thespring 58 and withdraws the valve 57 from its engagement with the valveseat 56 thereby allowing fluid to pass freely through the plug.Injection fluid thus remains in the drill stem during withdrawal of theplug. Following withdrawal of the cement wipe plug the mandrel is raisedslowly by raising the drill stem 16. Rotation of the mandrel ispreferably maintained while the mandrel is thus withdrawn. As soon aswithdrawal of the mandrel brings the exterior openings of the radialpassageways 17 above the level of cement in the bore hole circulation ofthe fluid through the drill stem and bore hole returns thus indicatingthat the mandrel is in position for injecting another batch of cement.At this point withdrawal of the mandrel is terminated and a second batchof cement may be injected. During injection of the second batch ofcement the lower portion of the mandrel below the radial passageways 17is centered in the bore hole by the previously injected and set cement.By thus utilizing previously injected cement to centralize the lower endof the mandrel it is unnecessary to replace the pull olf centralizerwhich was used to centralize the mandrel raised for injection of thenext batch of cement. In this manner the time required for the initialcure of the cement may be as little as about 1 hour.

Since the exterior of the mandrel serves to finish the interior of thecement casing as the mandrel is rotated and raised it is preferred thatthe mandrel be constructed with an external surface of low roughness.This may be achieved by any suitable means such as the use of analuminum or stainless steel mandrel or any other suitable low roughnessalloy or material. The use of a high lubricity mandrel coating such aspolyethylene or Teflon is also suitable to achieve the desired lowroughness on the exterior surface of the mandrel.

By recording the volume of cement injected in each batch and thedistance the mandrel is raised in order to bring the radial passagewaysof the mandrel above the injected cement it is possible to plot a holediameter log giving the relative bore hole diameter through each cementinjection stage. Such information is useful in many well operationproblems, particularly in perforating where it is useful to know howmuch of the actual earthen formation was penetrated by the perforatingbullets, jets, etc.

As mentioned above, the one way check valve H1 the bottom of the mandrelpermits fluid to pass freely through the passageways 18 to the spacebelow the mandrel. Thus, as the mandrel is raised, wash fluid is free topass through the mandrel via the passageways 1S and valve 19. Thisserves to balance forces on the newly injected cement and aids inpreventing slumping of the cement until further curing of the cementoccurs and the casing attains a greater measure of its ultimatestrength. 7

The removal of filter cake deposited by drilling fluids is a problemwhich is encountered in preparing most bore holes for cementing. Thisproblem is solved with the cementing tool of the present invention bythe use of a formation scratcher such as the formation scratcher 41described above. As the mandrel is rotated and raised preparatory toinjecting batches of cement as described above, the formation scratcherscrapes away from the hole walls any filter cake not previously purgedby other means such as mud acid or hole clean up solutions. Solid filtercake thus dislodged from the bore hole walls is collected by thecollecting collar 42 and washed through the peripheral passageways 18with wash fluid as the mandrel is raised. v

By utilizing the cementing tool of the present inveri= tion as describedabove, the mandrel of the cementing tool acts as a slip form for theplacement of cement in the hole in successive stages. Continuous orintermittent rotation of the mandrel during setting of each cement stageinsures freedom to raise the mandrel to the proper position forinjecting the next stage of cement while also providing a smoothfinished surface on the cement casing which is more impervious to acidand bacterial attack than is an unfinished cement surface. It has beenfound in practice that a comparatively small amount of torque isrequired to rotate the mandrel. For instance less than 2 foot pounds perlinear foot of cement fillup on the mandrel is needed to rotate amandrel having an outside diameter of 5 inches during the setting ofneat cement. Mandrel lengths of up to 100 or even 200 feet are thuspracticable.

The radial pasageways 17 of the mandrel are prefera= bly slanted in aslightly downward direction as shown in FIGURE 1 in order to assist infilling the portion of the bore hole below the passageways 1 .7 in theinitial stage and also to aid in cleaning the top of the previous Cement column prior to injection of the next subsequent cement stage. Thepassageways 17 are also preferably polished and tapered or flaredoutwardly in order to prevent plugging of these passageways with cement.

The batchwise placement of cement by the use of the cementing toolconstructed in accordance with the present invention enables varioustypes of cement to be placed in the same hole relative to theirrespective areas of use or need. For instance, permeable cement may beplaced opposite zones of possible hydrocarbon production while placementof possolanic mixes or other cements of simi larly impermeable naturethrough gas cap areas helps contain the gas as an energy sourse forproducing oil zones below the gas. Likewise, other special cements suchas latex cements or high temperature or sulfate resisting types may beused in particular areas as needed or desired.

While the invention has been described with respect to a preferredembodiment thereof, it will be apparent to those skilled in the art thatvarious changes and modifications may be made without departing from thespirit and scope of the invention and it is intended to cover all suchchanges and modifications in the appended claims.

We claim:

1. Apparatus of the character described comprising a generallycylindrical mandrel having a first longitudinal fluid passagewayextending from the upper end thereof and terminating within the lowerportion thereof, a fluid passageway extending from the lower portion ofsaid first lon itudinal passageway to the exterior of said mandrel, anda second longitudinal passageway for carrying fluid rom an exteriorspace adjacent the upper portion of said mandrel to a space below saidmandrel; a one way check valve in fluid communication with said secondlongitudinal passageway and adapted to allow fluid to pass from saidsecond longitudinal passageway to the space below said mandrel; a wipeplug of a suitable size and shape to be forced down said firstlongitudinal passageway and retrieved therefrom; means carried by saidwipe plug for retrieving the wipe plug; said wipe plug having valvemeans therein for permitting passage of fluid through said wipe plugonly while said wipe plug is being retrieved.

2. Apparatus of the character described comprising a generallycylindrical mandrel having an axial fluid passage-way extending from theupper end thereof and terminating within the lower portion thereof, aplurality of generally radial fluid passageways extending rom the lowerportion of said axial passageway to the exterior of said mandrel, and aplurality of longitudinally extending peripheral passageways forcarrying fluid from an exterior space adjacent the upper portion of saidmandrel to the bottom thereof; a one way check valve in fluidcommunication with said peripheral passageways and adapted to allowfluid to pass from said peripheral passageways to the space below saidmandrel; a wipe plug of a suitable size and shape to be forced down saidaxial passage- Way and retrieved therefrom; means carried by said wipeplug for retrieving the wipe plug; said wipe plug compris ing a bodyportion having a plurality of longitudinally spaced circumferentialflanges of resilient material extend ing outwardly therefrom, and saidwipe plug having valve means therein for permitting passage of fluidthrough said wipe plug only while said wipe plug is being retrieved.

3. A down hole cementing tool comprising in combination; a generallycylindrical mandrel having an axial passageway ex nding from the upperend thereof and terminating within the lower portion thereof and aplurality of generally radial fluid passageways extending from the lowerportion or" said axial passageway to the exterior of said mandrel; aformation scratcher extending radially outward from the upper portion ofsaid cementing tool and adapted to dislodge filter cake from the wallsof a hole as the cementing tool is rotated and raised therein; acollect. g collar extending outwardly and upwardly from said mandrel andencircling said mandrel immediately below said formation scratcher, saidcollecting collar being ada ted to catch particles of filter cakedislodged by said formation scratcher; said mandrel also being providedwith a plurality of longitudinally extendperipheral passageways forcarrying fluid from the space within said collecting collar and exteriorof said mandrel to the bottom of said mandrel; a one way check valve influid communication with said per pheral passageways and adapted toallow fluid to pass from said eripheral passageways to the space belowsaid mandrel; a cement wipe plug adapted to be forced down said an outerlongitudinally extending circumferential jacket having a plurality oflongitudinally spaced circumferential flanges of resilient materialextending outwardly therefrom, a liner of non-resilient material withinsaid jacket, said liner forming at least a portion of a generallycylindrical valve chamber, the lower end of said valve chamber having avalve seat, means for admitting fluid to said valve chamber, valve meansadapted to engage said valve seat to prevent flow of fluid through saidvalve chamber, spring means urging said valve means into engagement withsaid valve seat, the upper end of said wipe plug being provided withmeans for the p ssage of fluid; and retrieving means for retrieving saidwipe plug and removing said valve means from said valve seat.

4. A down hole cementing tool comprising a generally cylindrical mandrelhaving an axial passageway extending from the upper end thereof andterminating within the lower portion thereof and a plurality ofgenerally radial fluid passageways extending from the lower portion ofsaid axial passageway to the exterior of said mandrel; a formationscratcher extending radially outward from the upper portion of saidcementing tool and adapted to dislodge filter cake from the walls of ahole as the cementing tool is rotated and raised therein; a collectingcollar extending outwardly and upwardly from said mandrel and encirclingsaid mandrel immediately below said formation scratcher, said collectingcollar being adapted to catch particles of filter cake dislodged by saidforma tion scratcher; said mandrel also having a plurality oflongitudinally extending peripheral passageways for carryfluid from thespace within said collecting collar and exterior of said mandrel to thebottom of said mandrel; and a one way check valve in fluid communicationwith said peripheral passageways and adapted to allow fluid to pass fromsaid peripheral passageways to the space below said mandrel.

5. A down hole cementing tool comprising a generally cylindrical mandrelhaving a first longitudinal passageway extending from the upper endthereof and terminating within the lower portion thereof and a fluidpassageway extending from the lower portion of said first longitudinalpassag way to the exterior of said mandrel; a formation scratcherextending radially outward from the upper portion of said cementing tooland adapted to dislodge solids from the walls of a hole as the cementingtool is rotated and raised therein; a collecting collar extendingoutwardly and upwardly from said mandrel and encircling said mandrelimmediately below said formation scratcl er, said collecting collar beinadapted to catch solid material dislodged by said formation scratcher;said mandrel also having a second longitudinal passageway for carryingfluid from the space within said collecting collar and exterior of saidmandrel to the space below said mandrel; and a one way checl; in fluidcommunication with said second longitudinal passageway and adapted toallow fluid to pass from said second longitudinal passageways to thespace below said mandrel.

6. A down hole cementing tool comprising a generally cylindrical mandrelhaving an axial passageway extending from the upper end thereof andterminating within the lower portion thereof, a plurality of generallyradial fluid passageways extending from the lower portion of said axialpassageway to the exterior of said mandrel and a plurality oflongitudinally extending peripheral passageways for carrying fluid froman exterior space adjacent the upper portion of said mandrel to thebottom of said mandrel; a one way check valve in fluid communicationwitn said peripheral passageways and adapted to allow fluid to pass fromsaid peripheral passageways to the space below said mandrel; a fixedcentralizer connected to the upper portion of said cementing tool; and adetachable centralizer attached to the lower portion of said mandrel soas to be readily removable therefrom by raising said mandrel while saiddetachable centralizer is embedded in at least partially cured cementsurrounding the lower portion of said mandrel.

7. Apparatus of the character described comprising in combination; agenerally cylindrical mandrel having an axial passageway extending fromthe upper end thereof and terminating within the lower portion thereof,a plurality of generally radial fluid passageway extending from thelower portion of said axial passageway to the exterior of said mandrel,and a plurality of longitudinally extending peripheral passageways forcarrying fluid from a space adjacent the upper portion of said mandrelto the bottom thereof; a one-way check valve in fluid communication withsaid peripheral passageways and adapted to allow fluid to pass from saidperipheral passageways of the mandrel to the space below the mandrel; aretrievable wipe plug of suitable size and shape to be 7 forced downsaid axial passageway and retrieved therefrom; and means for retrievingsaid wipe plug; said wipe plug having valve means associated therewithoperable by said retrieving means for permitting passage of fluidthrough said wipe plug only while said wipe plug is being re ieved.

8. Apparatus of the character described comprising tubing adapted to belowered down a bore hole for injection of fluid therethrough; agenerally oylindrioal mandrel operatively connected with the lowerportion of said tubing; said mandrel having an axial fluid passagewayextending from the upper end thereof and terminating Within the lowerportion thereof, a plurality of generally radial fluid passagewaysextending from the lower portion of said axial passageway to theexterior of said mandrel, and a plurality of longitudinally extendingperipheral passageways for carrying fluid from a space adjacent theupper portion of said mandrel to the bottom thereof, said axialpassageway of the mandrel having substantially the same internaldiameter as the tubing and being in fluid communication and coaxial withsaid tubing; a oneway check valve in fluid communication with saidperipheral passageways and adapted to allow fluid to pass from saidperipheral passageways to the space below said mandrel; a wipe plug or"a suitable size and shape to be forced down said tubing and axialpassageway and retrieved therefrom; and a line attached to said wipeplug for retrieving the same; said wipe plug having valve meansassociated therewith operable by said line for permitting passage offluid through said wipe plug only while said wipe plug is beingretrieved.

References Cited in the file of this patent UNITED STATES PATENTS158,865 Pontez Jan. 19, 1875 1,466,986 Burgher Sept. 4, 1923 1,656,526Lincoln Jan. 17, 1928 1,669,130 Jensen May 8, 1928 2,141,370 Armentroutet al Dec. 27, 1938 2,253,537 Scaramucci Aug. 26, 1941 2701,019 SteedFeb. 1, 1955 2,740,480 Cox Apr. 3, 1956 2,897,524 Varner et al. Aug. 4,1959 2,941,594 Ladd et al. June 21, 1960 2,999,545 Bigelow Sept. 12,1961

1. APPARATUS OF THE CHARACTER DESCRIBED COMPRISING A GENERALLYCYLINDRICAL MANDREL HAVING A FIRST LONGITUDINAL FLUID PASSAGEWAYEXTENDING FROM THE UPPER END THEREOF AND TERMINATING WITHIN THE LOWERPORTION THEREOF, A FLUID PASSAGEWAY EXTENDING FROM THE LOWER PORTION OFSAID FIRST LONGITUDINAL PASSAGEWAY TO THE EXTERIOR OF SAID MANDREL, ANDA SECOND LONGITUDINAL PASSAGEWAY FOR CARRYING FLUID FROM AN EXTERIORSPACE ADJACENT THE UPPER PORTION OF SAID MANDREL TO A SPACE BELOW SAIDMANDREL; A ONE WAY CHECK VALVE IN FLUID COMMUNICATION WITH SAID SECONDLONGITUDINAL PASSAGEWAY AND ADAPTED TO ALLOW FLUID TO PASS FROM SAIDSECOND LONGITUDINAL PASSAGEWAY TO THE SPACE BELOW SAID MANDREL; A WIPEPLUG OF A SUITABLE SIZE AND SHAPE TO BE FORCED DOWN SAID FIRSTLONGITUDINAL PASSAGEWAY AND RETRIEVED THEREFROM; MEANS CARRIED BY SAIDWIPE PLUG FOR RETRIEVING THE WIPE PLUG; SAID WIPE PLUG HAVING VALVEMEANS THEREIN FOR PERMITTING PASSAGE OF FLUID THROUGH SAID WIPE PLUGONLY WHILE SAID WIPE PLUG IS BEING RETRIEVED.